DE1260606B - Control circuit with transistors with low quiescent current consumption - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

H 02 j

German KL: 21 dl - 69

Number: 1260 606

File number: N 26179 VIII b / 21 dl

Filing date: February 6, 1965

Open date: February 8, 1968

The invention relates to a control circuit with transistors with low quiescent current consumption which the current through a load, e.g. B. an electric motor in which direction is reversible and in which two transistors of the same conductivity type are provided, their emitter-collector paths in Series with one connected between the collector of the first and the emitter of the second transistor Diode are connected to a DC voltage source, the load being applied to the connecting line this diode is connected to the emitter of the second transistor. Such a device is already proposed in the earlier German patent 1182303. There are several in this patent Means for limiting the quiescent current consumption specified (the quiescent current flows through the Transistors when the control signal is zero); these measures involve the application of an additional Supply voltage source with itself. In practice, this source must be used to achieve a satisfactory Effect can deliver a relatively high voltage, which undesirably high energy consumption entails and also requires the use of transistors for this higher Tensions are measured.

The invention is based on the object of specifying a simple measure by which the Use of such a voltage source is unnecessary. It is characterized in that each a current limiting element in the common line of the collector of the first and the base of the second transistor is inserted. The current value of this current limiting element is preferably at at which the limitation begins, approximately the same as that flowing through the load at maximum modulation Current divided by the collector-base current gain factor of the second transistor. as The current limiting element is expediently a resistor with a high positive temperature coefficient used.

The invention is explained in more detail with reference to the drawing, in which

F i g. 1 shows a first embodiment and

F i g. 2 illustrate a second embodiment of the invention.

The embodiment according to FIG. 1 contains a first transistor 1 and a second transistor 2 of the same conductivity type (in the illustrated case of the pnp type). The emitter-collector paths of the transistors 1 and 2 are connected in series with a diode 3 connected between the collector of the first and the emitter of the second transistor to the Klem control circuit with transistors with low
Quiescent power consumption

Applicant:

N.V. Philips' Gloeilampenfabrieken, Eindhoven

(Netherlands)

Representative:

Dr. H. Scholz, patent attorney,

2000 Hamburg 1, Mönckebergstr. 7th

Named as inventor:

Anne Hendrik Bruinsma,

Johannes Meijer Cluwen, Eindhoven

(Netherlands)

Claimed priority:

Netherlands 11 February 1964 (6 401113) -

men B + or B - connected to a supply source. An electric motor 4 is connected to the connection line between the diode 3 and the emitter of the second transistor 2. The other terminal of the motor 4 can be connected to a point of fixed voltage, the value of which lies between that of the voltages prevailing at the terminals B + or B -. In the case shown, however, a second set of transistors 1 'and 2' connected in the same way and a diode 3 'are used. The switches 5 and 5 'are used to take the device out of operation when the rotor of the motor 4 has reached a certain position. Resistors 6 and 6 'are provided in the collector lines of transistors 2 and 2' in order to avoid overloading transistors 2 and 2 '. If a control voltage is applied between the terminals 7 and 7 ', whereby a control current of the base electrodes of the transistors 1 and 1' is achieved via the transistors 8 and 8 ', it is achieved that, for example, the current through the transistor 1 increases, while that through the Transistor 1 'decreases. As a result, the voltage drop across the resistor 9 provided in the common line of the collector of the first transistor 1 and the base of the transistor 2 will increase, so that the transistor 2 becomes less conductive. In a corresponding way, the clamping

809 507/246

Claims (2)

3 4 nungsf all over the corresponding resistor 9 'from- To achieve the highest current through the Monehmen, whereby the transistor 2' more current tor 4, the transistor 2 must be maximally conductive, the transistor allows through. In this case, however, it will be blocked by the sistor 2 '. The voltage drop motor causes a current to flow in the direction of the arrow. over the transistors 1 'and 2 is then negligible - on the other hand, by means of the control voltage between 5 bar compared to the voltage drop over the motor 4, the terminals 7 and 7', the transistor 1 is less and (also the diode 3 'must be as low as possible) the transistor 1 'made more conductive so the voltage drop reverses in the forward direction), current through the motor 4 reverses its direction and while the current through the transistors 1 and 2' will thus flow in the opposite direction to the arrow. One then is negligible. In this state, there is a similar effect when either the io advantageous when the effective resistance of the EIe terminal 7 or T a pulsed control voltage Mentes 9 has the lowest possible value, so that either the transistors 8 are supplied with the base current of transistor 2 despite the low and 1 or transistors 8 'and V are opened voltage drop across element 9 is sufficient, the. The arrangement is dimensioned in such a way that in the around this transistor 2 in the state of saturation to the rest position - the state in which no control voltage 15 hold. voltage between the terminals 7 and 7 '. If the current is applied from the aforementioned state - the current through the motor 4 is just zero. increased by the transistor 1 and that by the The diodes 3 and 3 'bring about that the transistor 1' is reduced, so this current increase Transistors 2 and 2 'are non-conductive in this case. soon a very large increase in the effective cons-on the other hand leads to a slight decrease in the current 20 level of the element 9 '. Since that through the transistor 1 (or Γ) compared to the element 9 each increase in the passing current This quiescent state to the fact that the diode 3 (or 3 ') counteracts the aforementioned increase in current blocks, whereby the transistor 2 (or 2 ') conductive through the transistor 1, a corresponding decrease will. of the base current of transistor 2 result. To achieve a high maximum current through 25, the decrease in the current Motor 4 is a low value of the resistor 9 mes through the transistor 1 a corresponding Zudesired; in the arrangement according to the older pa the base current of the transistor 2 'would take with it As a result, however, tent will bring a proportionate effect. The idle state is reached when the caused high quiescent current setting. In general, the current through the motor 4 is just zero, ie when The quiescent current consumption could mean completely 30 at the emitters of the transistors 2 and 2 'the same be suppressed by transistors opposing potential prevails. To achieve this potential Conductivity type can be used, but there must be transistor 1 in the earlier patent it follows that not always transistors for high a relatively high current through the ver currents and of opposite conductivity type relatively low resistance 9 send to be available. In the case of the amplifier circuit 35, a sufficient voltage drop is to be achieved over it the earlier patent may have the disadvantage of a len. Sufficient for the measure according to the invention to high quiescent current consumption are reduced, a significantly lower current, as a result of the increase the resistor 9 (or 9 ') to a higher menden effective resistance of the element 9 of the (negative) voltage is connected when the KoI voltage drop increases very quickly over it, lector of transistor 2 (or 2 '). However, this has the 40 In the exemplary embodiment according to FIG. 2 become Disadvantage that more energy is dissipated while the same by corresponding reference numerals the transistor 1 (or 1 ') a higher drawn switching elements applied as in Fig. 1. Must withstand tension. The control of the transistor 8 'is from the collector According to the invention, the resistor 9 (or 9 ') gate voltage of the transistor 1 is formed by means of a span, a current limiting element. Such 45 voltage divider 11, 12 derived. Next is in the ge current limiting elements are known per se. As a common emitter line of the transistors 1 and 1 ', examples are mentioned: ceramic resistors with a diode 13 inserted, which have a low threshold of a high positive temperature coefficient, e.g. B. value voltage in the emitter circles of the transistor based on barium titanate, the dynamic value of which causes 1 or 1 '. Furthermore, an additional derstandswert is provided for a temperature increase of 50 transistor 14, which can control transistor 8 by a few decades (which is static. To avoid unnecessary energy loss, measured current-voltage characteristics can even be the transistors 8 and 8 'and 14 have a negative resistance part on an auxiliary feed); Furthermore, semiconductor diodes driven in the source with a lower voltage and lower reverse direction, which are connected under current as the supply source, which is connected between the action of incident radiation and a practical terminal B + and B -. allow constant current to pass through the table; Field effect transistors, whose gate electrode ("gate") with the source patent claims: electrode ("source") or with one of the current channel of the field effect transistor narrowing voltage 1. Control circuit with transistors with low is bound. 60 like quiescent power consumption at which the power The current-limiting element 9 (or 9 ') has been subjected to a load, e.g. B. an electric motor, preferably a current value at which the limitation is reversible in the direction and at which and which is approximately equal to that of a maximum of two transistors of the same conductivity type Modulation through the motor flowing current are provided, the emitter-collector section of which divides through the collector-base current amplification 65 ken in series with one between the collector factor of the second transistor is 2 (or 2 '). At the one of the first and the emitter of the second Transer maximum modulation is z. B. the transistor 1 sistors switched-on diode blocked to a DC voltage and the transistor 1 'is completely conductive. power source are connected, whereby the loading load connected to the connecting line of this diode to the emitter of the second transistor is, characterized in that each in the common line of the collector a current limiting element is inserted into the first and the base of the second transistor. 2. Control circuit according to claim 1, characterized in that the current of the current limiting element, at which the current limitation begins, approximately the same as that at maximum modulation current flowing through the load divided by the collector-base current gain factor of the second transistor is. 3. Control circuit according to claim 1 or 2, characterized in that as a current limiting element a resistor with a high positive temperature coefficient is used. Legacy Patents Considered:
German Patent No. 1182 303. 1 sheet of drawings 809 507/246 1.68 © Bundesdruckerei Berlin